This invention relates to a piping apparatus for melting snow and ice. More particularly, the present invention relates to a piping apparatus for melting snow and ice which is suitable for preventing freezing and snowfall of a surface-like facility or surface-like structure such as a road, a bridge, the roof of a building, a parking lot, a ground, a snow dumping facility, and the like, and for melting the ice after freezing and the snow after snowfall.
Prevention of snowfall and snow removing from the roofs of houses and buildings have been made by use of electric heat in some parts of areas of high snowfall but snow removing has mostly been carried out by workers. However, this snow removing work from the roofs needs a great deal of labor every year and it has become a serious social problem because not a few accidentally drop from the roofs and are killed in the snow removing work.
On the other hand, various methods have been employed in the past in order to prevent snowfall and freezing and to melt the snow and ice in public facilities such as roads, parking lots, bridges, grounds, and the like, in areas of high snowfall and cold districts. These methods include a method which lays down sprinkler for spraying water, a method which sprays calcium chloride, a method which lays down electric heat wires under the ground to melt the snow by electric heat, a heat pipe system which melts the snow by utilizing the heat generated when a liquefied gas is boiled for evaporation at a low temperature, and so forth.
However, the sprinkler system involves the problem that the nozzles are likely to be choked up with sands and gravels and when it utilizes the underground water, the subsidence of ground is likely to occur due to dry-up of the underground water.
The spraying method of calcium chloride needs a great deal of labor for spraying and invites not only the wither of trees and grasses but also corrosion of cars due to salt. Further, the method which utilizes the electric heat consumes large quantities of electric power and is hence not practically economical.
The heat pipe system is not free from the problems in that the pipe itself is expensive, high facility investment is necessary and moreover, double facility investment is necessary because the portions into which the liquefied gas must be warmed up in the cold districts. When the terrestrial heat is used, its efficiency drops with the passage of time.
In cities, on the other hand, emergency snow removal is effected in order to prevent a traffic jam due to snowfall and the snow transported by dumping trucks are discarded into snow dumping facilities or into rivers. However, the snow dumping facilities have limited capacity and will get into saturation, while dumping of snow into the rivers will result in pollution of rivers and environment.
In the particular case of roads, a hot water pipe snow melting method has been attempted in recent years which arranges hot water pipes below the road surface, circulates the hot water from a hot water boiler through the hot water pipes to radiate the heat and thus prevents the snowfall and freeze of the road surface and melts the snow and ice. In accordance with this method, two pipes a and b are arranged in parallel with each other and are bent zigzag many times as depicted in FIG. 20(A) of the accompanying drawings and one of the ends of each pipe a, b is connected to a hot water feed pipe c with the other end being connected to a hot water return pipe d in order to circulate the hot water as represented by arrows in the drawing. Alternatively, a single pipe e is bent zigzag many times as shown in FIG. 20(B) and one of the ends of this pipe e is connected to the hot water feed pipe c while the other end is connected to the hot water return pipe d to circulate the hot water as represented by the arrows. In either case, one or two pipes are arranged zigzag below the road surface. Therefore, in order to uniformly heat a wide road, the length of the road covered is small in comparison with the length of the pipe or pipes used. If the length of the pipe(s) is increased extremely in order to increase the coverage, the temperature of the hot water drops at the end of the flowing direction of the hot water so that the road surface cannot uniformly be heated, after all, for a long distance. Moreover, even if any damage or pin-holes occur at part of the pipes, it is difficult to discover that part and a great deal of labor is necessary for maintenance and inspection.